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Official commercial channel

Grok 4.5 API

xAI’s "Opus-class but faster and cheaper" pitch — and the list price backs it up.

  • Context

    500K

  • Max output

    64K

  • Serving precision

    Vendor-managed

  • Licence

    Proprietary

Grok 4.5 shipped to developers on 8 July 2026 with a 500K-token context window, text and image input, tool calling, structured outputs, web search and extended reasoning. Artificial Analysis ranks it #4 of 168 models on its Intelligence Index at a score of 54, while vendor list pricing sits at $2 per million input and $6 per million output ($0.50 for cached input) — noticeably below same-tier proprietary rivals. Worth knowing: the window is actually smaller than Grok 4.3’s 1M.

Proprietary, provided through the vendor’s official commercial licensing. Contract, invoice, audit trail — not an account pool and not a reverse-engineered client protocol.

Specifications

Model ID
grok-4.5
Published by
xAI
How it is served
Official commercial channel
Licence
Proprietary
Context
500K
Max output
64K
Serving precision
Vendor-managed
Input modalities
Text · Image
Released
2026-07-08

What it is good at

Near-frontier at a lower tier of price
#4 on the Intelligence Index while listing at $2 input and $6 output per million tokens. For pipelines chasing "strong enough and economical", it is hard to leave out of the comparison.
Cached input at a quarter of the rate
Cache hits bill at $0.50 per million input tokens. Agent loops with long system prompts and heavy shared prefixes land well under the headline rate in practice.
Web search is built in
Extended reasoning and web search are native capabilities, so time-sensitive questions do not require you to stand up a separate retrieval pipeline first.

Where it fits

  • Cost-sensitive pipelines that still want near-frontier capability
  • Agents with long system prompts that hit cache heavily
  • Q&A and research that depends on current information
  • Cost/quality comparisons against the Claude and GPT flagships

Three steps

Change one line of base_url, put the model ID below in the `model` field, and leave the rest of your code alone.

model: "grok-4.5"

curl https://api.nexaix.net/v1/chat/completions \
  -H "Authorization: Bearer $NEXAIX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "grok-4.5",
    "stream": true,
    "messages": [
      { "role": "user", "content": "Summarise this contract." }
    ]
  }'

About this model

Why is 4.5’s context smaller than 4.3’s?

It is: 4.5 ships 500K where 4.3 had 1M. xAI traded window for speed and token efficiency this generation. When you need a million-token window we also carry GLM-5.2, DeepSeek V4, Kimi K3, Claude Opus 5 and the GPT-5.6 family.

Do requests over 200K tokens cost more?

Yes. The vendor bills requests exceeding 200K total tokens at a higher tier. Build that step into your long-context cost estimates.

Is your Grok an official channel?

Yes. Like every proprietary model we carry, it comes through the vendor’s official commercial licensing — contract, invoice, audit trail — with no account pools and no reverse-engineered client protocols.

Also worth a look

Run your own eval on it

Take the trial credit, run the evals you already have against this model, and then decide whether it gets your production traffic.